Yellow because Pangea all the continents were together
Answer:
The period 4 alkaline-earth metal has the name Calcium. An isotope of this element having 20 neutrons has a mass number of 40.
Explanation:
Looking at the periodic table 4th row for the alkaline-earth metal, we can find Calcium which has an atomic number of 20 (or protons number, or z). The mass number is given by the sum of protons and neutrons. If the number of protons in this case is 20 and the number of neutrons is also 20, the mass number A = 40.
Answer:
The red light is refracted least. The violet light is refracted most.
Explanation:
E=mc (square) E= mass times capacity squared
<span>a. x and y are atoms of the same element.
If both atoms contain the same amount of protons, they are always the same element.
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